Cellular therapy to suppress immune response

Abstract

Disclosed herein are compositions comprising engineered antigen-specific Tregs that suppress antibody formation against the soluble therapeutic protein factor VIII in an MIC-independent fashion. Complexing TCR-based signaling with single-chain variable fragment (scFv) recognition to generate TCR fusion construct (TRUC)-Tregs delivered controlled antigen-specific signaling via engagement of the entire TCR complex, thereby directing functional suppression of the FVIII-specific antibody response.

1 . A method of modifying an inappropriate immune response in a patient receiving repeated doses of a therapeutic exogenous agent, said method comprising
 administering modified Tregs to said patient to suppress the formation of antibodies against the therapeutic agent, wherein said modified Tregs comprise a T cell receptor fusion construct (TRUC), said TRUC comprising
 variable heavy (VH) and light (VL) chains of an antibody with specificity to said therapeutic agent protein; and 
 a T cell receptor CD3 epsilon subunit, wherein said variable heavy (VH) and light (VL) chains are fused to the CD3 epsilon subunit optionally via a peptide linker. 
   
     
     
         2 . The method of  claim 1  wherein said TRUC comprises a single chain variable fragment (scFv) having specificity for said therapeutic agent fused to the N-terminus of a CD3ε subunit, optionally via a peptide linker. 
     
     
         3 . (canceled) 
     
     
         4 . The method of claim  3  wherein the administered Tregs are autologous that have been modified to comprises said TRUC. 
     
     
         5 . The method of  claim 2  wherein the therapeutic agent is clotting factor FVIII. 
     
     
         6 . The method of  claim 1  wherein the TRUC further comprises hinge regions selected from either murine or human CD28 or CD8. 
     
     
         7 . The method of  claim 1  wherein said Treg further expresses a gene encoding chemokine receptor CXCR5. 
     
     
         8 . (canceled) 
     
     
         9 . The method of  4  wherein said TRUC comprises an amino acid sequence having at least 95% sequence identity to SEQ ID NO: 4. 
     
     
         10 .- 15 . (canceled) 
     
     
         16 . An engineered Treg, where the endogenous TCR-CD3 signaling is reconfigured to respond to scFv-based recognition, said Treg expressing
 i) a TCR fusion construct comprising
 a single chain variable fragment (scFv) having specificity for a preselected therapeutic agent, said scFv being fused to the N-terminus of a CD3ε subunit, optionally via a peptide linker. 
   
     
     
         17 . The engineered Treg of  claim 16  wherein the Treg further expresses an additional gene, Programmed Death Ligand 1 (PDL1). 
     
     
         18 . The engineered Treg of  claim 16  wherein said Treg further expresses a gene encoding chemokine receptor CXCR5. 
     
     
         19 . The engineered Treg of  claim 18  wherein said scFv has specificity for clotting factor FVIII. 
     
     
         20 . The engineered Treg of  claim 19  wherein said scFV specifically binds to amino acid residues 2125-2332 of human FVIII. 
     
     
         21 . The engineered Treg of  claim 16  wherein the TCR fusion construct further comprises hinge regions selected from either murine or human CD28 or CD8. 
     
     
         22 . The engineered Treg of  claim 16  wherein said TCR fusion construct comprises an amino acid sequence having at least 95% sequence identity to SEQ ID NO: 4. 
     
     
         23 . The engineered Treg of  claim 16  wherein said TCR fusion construct comprises an amino acid sequence corresponding to SEQ ID NO: 4, wherein the murine amino acid sequences have been substituted with the corresponding human equivalent amino acid sequences. 
     
     
         24 . A TCR fusion construct comprising
 single chain variable fragment (scFv) having specificity for clotting factor FVIII fused to the N-terminus of a CD3ε subunit, optionally via a peptide linker.   
     
     
         25 . The TCR fusion construct of  claim 24  comprising an amino acid sequence having at least 95% sequence identity to a sequence selected from SEQ ID NO: 2 or 4. 
     
     
         26 . The TCR fusion construct of  claim 24 , wherein a nucleic acid construct comprises a polynucleotide encoding the TCR fusion construct comprising single chain variable fragment (scFv) having specificity for clotting factor FVIII fused to the N-terminus of a CD3ε subunit, optionally via a peptide linker. 
     
     
         27 . The nucleic acid construct of  claim 26  further comprising a nucleic acid sequence encoding Programmed Death Ligand 1 (PDL1). 
     
     
         28 . The nucleic acid construct of  claim 26  wherein said nucleic acid has at least 95% sequence identity to a sequence selected from SEQ ID NO: 1 or 3.